Catostomus vs fish genus

Catostomus and fish genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
Catostomus	Yes	No	No	No
fish genus	Yes	No	No	No

As nouns, fish genus is a hypernym of Catostomus; that is, fish genus is a word with a broader meaning than Catostomus:

Catostomus (noun)	fish genus (noun)
type genus of the family Catostomidae	any of various genus of fish